1. Field of the Invention
This invention relates to novel demulsifier compositions, and to methods of preparation and use thereof, and more particularly to novel demulsifying agents for use in processes adapted for preventing, breaking or resolving emulsions of the water-in-oil type, especially petroleum emulsions.
2. Prior Art
A wide variety of oxyalkylated materials are known to be demulsifiers for the resolution of water-in-oil emulsions. For example, it is well known that demulsifiers have been prepared from the condensation of diglycidyl ethers with polyoxyalkylene glycols and that such demulsifiers have been used to resolve certain crude oil emulsions. Note, for example, U.S. Pat. Nos. 2,792,352-357 and U.S. Pat. No. 3,383,326 and EP Nos. 0 55 433-34.
It is also known that such compositions release the water resulting from the resolved emulsion faster and more completely when blended with suitable water coalescing agents such as oxyalkylated adducts of phenol-formaldehyde resins, polyalkylene polyamines and the like. Note U.S. Pat. No. 3,511,882.
Additional improvements have been realized by further heating and condensing such blends. Note U.S. Pat. No. 3,383,325. Moreover, the instant inventors' U.S. Pat. Nos. 4,502,977 and 4,626,379, disclose demulsifier compositions comprising the partially condensed reaction product of a blend of at least two oxyalkylated materials with a vinyl monomer. The oxyalkylated materials are polyoxyalkylene oxide copolymers, and at least one of the copolymers is derived from a polyoxyalkylene glycol and a diglycidyl ether. Such compositions are partially cross-linked.
It is also known that water-in-oil emulsions may be resolved by demulsifiers resulting from the reaction of a polyoxyalkylene alcohol with an unsaturated reactant and further reacting the product so formed with an oxygen or nitrogen-containing vinyl addition monomer to afford polyhydric substituted polyethylene backboned emulsion breakers. Note Canadian Patent No. 1,010,740.
Particular demulsifiers useful in the oil processing and servicing industries have been found to have varying effectiveness, depending in large part on the highly disparate conditions, for example, oil field characteristics, in which the demulsifiers are used. Thus, despite the fact that many demulsifiers have been found for resolving water-in-oil emulsions, the oil processing and servicing industries are continually looking for more effective demulsifiers.